The present invention concerns fuses for various sub-munitions to be carried in cargo projectiles such as rocket warheads, aircraft dispensers, mortar bombs, artillery shells and quite generally any type of ground or air launched warhead adapted to carry sub-munition.
In the following description and claims the term "cargo warhead" will be used for the comprehensive warhead, the term "cargo warhead grenade" will be used for the individual sub-munitions and the term "cargo projectile" will be used for the carrier of the grenades regardless of its type and the manner in which it is launched.
In cargo warheads the cargo projectile comprises means by which after launching, the individual grenades are ejected. After their ejection the grenades continue in their flight towards the target where they arrive with a statistical spread. The grenades may be optimised for specific purposes, such as anti-armour, anti-personnel or others.
The fuse of a cargo warhead grenade comprises a striker pin assembly having a striker pin movable between forward, retracted and striking positions and adapted to be locked in the forward position. When the grenades are packed into the cargo projectile, the striker pin in each fuse is unlocked but remains in the forward position until the fuse is armed. For arming, the shaft of the striker pin assembly has a portion which protrudes outside the fuse, housing and is fitted at its protruding end with drag producing means of stabilization such as, for example, a drag tape, to be referred to hereinafter occasionally as "drag producing means". When the grenade is ejected from the cargo projectile it begins to spin around its longitudinal axis and in consequence of this spin the drag producing means retract the striker pin assembly whereby the fuse is armed and the striker pin assembly remains in the retracted position until the grenade hits the target. When the grenade hits a target the inertia forces acting on the striker pin assembly drive it into the striking position with a force which, as a rule, is sufficient to detonate the fuse detonator.
In one known type of cargo warhead grenade fuses, the path of the striker pin assembly is blocked in the unarmed position and upon the release of the grenade from the cargo projectile and consequential retraction of the striker pin, the blockage is automatically removed whereupon the fuse is armed. The means for blocking the path of the striker pin in such a fuse may, for example, be in the form of a slidable member biased into a non-blocking position and locked in the blocking position by the striker pin itself. When the striker pin is retracted in consequence of the action of the drag producing means the striker pin is withdrawn from engagement with the slidable member whereupon the latter moves automatically into a non-blocking position, clearing the path of the striker pin to the detonator. In this way the fuse is armed and when the grenade hits the target the striker pin advances by force of intertia towards the detonator whereupon the latter is detonated and the grenade explodes.
Recently a new type of fuse for a cargo warhead grenade has become known. Essentially, in this type of fuse the means for blocking the striker pin assembly prior to arming are replaced by a slider that carries the detonator and is so designed that in the unarmed state of the fuse the detonator is out of alignment with the striker pin and is brought into alignment with the pin only when the fuse is armed upon retraction of the striker pin assembly by the action of the drag producing means upon ejection of the grenade from the cargo projectile. This type of cargo warhead grenade fuse will be referred to hereinafter as the slider type fuse.
The present invention is concerned with an improved slider type fuse for a cargo warhead grenade.
Basically, cargo warhead grenade fuses are impact fuses and the detonation is as a rule conditional on the grenade hitting a hard target which produces a sharp impact. Where, however, the target is soft, such as in the case of high vegetation or snow, the impact of the grenade may be insufficient to create the inertia forces required for the striker pin to travel all the way towards the detonator to detonate the latter, with the consequence that the dud rate may be unacceptably high, endangering friendly units if such will enter the impact area.
There may also be other reasons for malfunctioning of the striker pin, e.g. the presence of some sort of obstruction which impedes the movement of the striker pin with the consequence that the grenade will not explode even where it hits a hard target. Such malfunctioning may again give rise to duds liable to endanger friendly units.
It is accordingly the object of the present invention to provide an improved cargo warhead grenade fuse of the slider type comprising means for initiating the explosion of the grenade in case the normal fuse mechanism does not function.